Consumable electrode

ABSTRACT

A method of producing active ingredients of the sodium initiator and calcium moderator of a consumable electrode as a flocculant mixture in a single process operation extending from the point of their reduction during electrolysis to their molten state and subsequent atomization and mixture with talc and depolarizer agents and their application in electrode construction. The consumable electrode is used in the electrolytic gas generator reaction chamber of a second-generation fuel cell.

CROSS REFERENCES

[0001] The present invention relates to my copending application Ser.No. 10/072,166 placed on file Feb. 11, 2002.

BACKGROUND OF THE INVENTION

[0002] A sodium-calcium mixture is produced as a micron size flocculantby the atomization of the molten metals produced at the cathode of anelectrolysis bath. In its flocculant form the sodium-calcium mixturecomprises the active ingredients of a consumable electrode used inhydrolysis within an electrolytic generator described in my copendingpatent of Ref. 1. The sodium component of the mixture is termed theinitiator because it reacts exothermally during hydrolysis liberatinghydrogen and generating sufficient heat at the intimate contactingsurface interface with the calcium metal, termed the moderator causingit to likewise hydrolize and produce hydrogen.

[0003] Two equivalent weights of the sodium initiator are required toproduce hydrogen in its diatomic molecular form with the generation of 2electrons.

2Na+2H₂O→2NaOH+H₂↑+heat+2 electrons

[0004] Therefore one equivalent weight of sodium initiator produces 1electron and a positively charged proton. The charged proton attaches toa water molecule to form a hydronium molecule (H₃O). The hydroniummolecules are discharged at the cathode releasing the hydrogen protons.Each pair of protons that are discharged at the cathode are joinedtogether by sharing an electron to form a diatomic molecule of gaseoushydrogen H₂↑.

[0005] The calcium metal moderator within the atomized flocculantmixture reacts with water to produce hydrogen but with greaterdifficulty requiring the application of heat. The necessary heat issupplied by the exothermic reaction of the sodium initiator which is inintimate contact with the calcium during hydrolysis.

Ca+2H₂O+initiator heat→Ca(OH)₂+H₂↑+2 electrons

[0006] In this latter instance 1 equivalent weight of the calciummoderator produces 2 electrons, thus doubling the electron discharge tothe electrolyte solution surrounding the cathode.

[0007] Because the process of electrolysis is reversible in hydrolysis,a 50/50 mixture of initiator and moderator produces at the cathode andanode of an electrolytic generator of the general type described in Ref.1, the sum of their fractional electrochemical equivalents, which inthis instance is 567.7 amp-hours per pound of sodium-calcium flocculantwithin the consumable electrode.

[0008] The melting point of sodium chloride is 804° C. (1479° F.) butwhen calcium chloride is added to the electrolysis bath the meltingpoint is lowered to approximately 600° C. (1112° F.). This significantlyreduces the costs of the reduction of the metal and extends the life ofthe atomization nozzle in the flocculation process when operating below700° C. (1292° F.). The sodium-calcium mixture of the molten metal arethe same as those active ingredients of Ref 1, but in the latterapplication their formulation is by dispersion in a heavy mineral oil orsilica based oil at room temperature. In the present invention themixing of the sodium-calcium mixture is carried out in the molten state.In the process, the beginning charge within the cell bath is typically58% calcium chloride and 42% sodium chloride by weight. At the elevatedtemperature of 600° C. the chlorine of each component is driven off andthe calcium metal becomes soluble in the molten sodium metal as amixture deposited at the cathode. The molten mixture is decanted into aheated processing chamber where it is forced under pressure through anatomizing nozzle orifice exiting as a thin stream that is broken up, andcooled below its freezing point, by a jet of compressed inert gas(nitrogen) into a micron size flocculant. The particulate size of theflocculant mixture depends upon the atomizing temperature and impingingangle and jet pressure.

[0009] In Ref. 1 silica powder and diatomaceous earth as well asmagnesium powders are separately added in measured quantities to analkali metal dispersion as drying agents and to also promote capillaryaction and surface adsorption in the migration of water into theelectrode when emersed in the electrolyte. In the present invention thesilica and magnesium are combined in mineral complex form as dehydratedtalc which is mixed with the sodium-calcium flocculant in the presenceof a depolorization agent. The capillary wicking action in the presentinvention is enhanced by enclosing the active ingredients of theinitiator and moderator within a fibrous paper membrane. When theelectrode is not to be used in a single continuous operation, but in aninterrupted fashion, the paper cylinder is flattened by calendering andsegmented, and separately sealed as discreet quantum's of stored energyplaced in separate compartment cells configured within the lower carrierinsulation and sealed by an over-lying aluminized conductor tape.Segmenting the tape in this manner prevents capillary migration of waterinto the unused portion of the tape during periods of inactivity orstorage.

[0010] In the larger designs where current flow and operatingtemperatures are higher aluminium wire is embedded along the tape edgeto assure tensile integrity and electrical continuity.

SUMMARY OF THE INVENTION

[0011] The invention is a consumable electrode comprising an alkalimetal initiator and an alkaline earth moderator each of which whenhydrolyzed reverses the electronic process of their cathodic reactionsduring their formative period of electrolysis to release within anelectrolytic generator, as described in Ref. 1, an electrochemicalequivalent current of equal quantity.

[0012] The primary objective of the invention is to provide a method bywhich the consumable electrode comprising a sodium initiator and calciummoderator which are produced simultaneously as a flocculant mixture in asingle process operation at the electrolysis bath station eliminatingthe procedural operating steps of calcium freezing point separation andsodium decanting and filtering processes and their subsequentparticulate recombination at room temperatures during the electrodemanufacture as described in my co-pending patent of Ref. 1. Producingthe sodium-calcium flocculant mixture at the point of their jointelectrolysis significantly lowers the production costs of the electrode.

[0013] It is yet another object of the invention to eliminate themineral oil or silica based dispersion medium of Ref. 1 to lower thecarbon content of the component elements comprising the formulation ofthe consumable electrode and thus decrease the level of contaminantcarbonate material found in the generator electrolyte and the amount ofcarbon dioxide in the cathode and anode liberated hydrogen and oxygengas streams respectively which poison the down-stream fuel celloperating in tandem with the generator.

[0014] And still it is yet another object of the invention to bring theinitiator and moderator into intimate contact in a manner that producesan increased surface interface between these two components such thatthe hydrolysis and subsequent oxidation of the calcium component at theinduced initiator higher exothermic temperature is more easily andefficiently attained facilitating the electron release of the calciumand increasing the electrochemical equivalent generating capacity of theelectrode.

[0015] Another object of the invention is to provide alternative systemwicking and thermal ballast material in the form of fibrous roving andpaper and mineral talc compositions respectively which may replace orsupplement and otherwise enhance electrolyte capillary action and thusimprove the uniformity of electrolyte diffusion within the electrode.

[0016] Still another object of the invention is to improve the tensileintegrity of the cathode carrier insulation and increase the assuranceof its electrical conductance at higher electrode current flow andoperating temperature by embedding metal wire within the said carrierinsulation.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Drawings are presented which show the method of manufacture ofthe active ingredients of the consumable electrode and the manner oftheir assembly between the electrode carrier insulation and conductorcover tape.

[0018]FIG. 1 Is a diagrammatic cross-section of an electrolysis bathconnected in series flow with an atomizing chamber for the production ofa sodium-calcium flocculent.

[0019]FIG. 2 Is a drawing of a length of carrier insulation andaluminized conductor tape showing the general features of theirconstruction and the intervening segmented active ingredients of thesodium initiator and calcium moderator calendered upon a paper or glassroving wick material creating a wicking element.

[0020]FIG. 3 Is a drawing of a cross-section of the consumableelectrode.

[0021]FIG. 4 is a cross-section of the consumable electrode showing animbedded wire conductor at each edge.

DETAILED DESCRIPTION OF THE INVENTION

[0022] The invention is a consumable cathode electrode that is to beused for the splitting of hydrogen protons from water with thesimultaneous generation of a corresponding electrochemical equivalentcurrent flow within a caustic electrolyte solution of a sodium hydrogengenerator.

[0023]FIG. 1 is a flow schematic, shown principally in cross-section, ofan electrolysis bath 1 in series circuit with a heated process chamber2, a pressure pump 3, an atomizing nozzle 4, an inert gas blast nozzle5, an atomization chamber 6, a sodium-calcium flocculant product bin 7,holding the flocculant 8 and the screw conveyer 9 that moves theflocculent to a rotating tumbler where it is thoroughly mixed with adehydrated talc and trace amounts of a depolarizer agent. Theelectrolysis bath 1 of FIG. 1 is comprised of a charging gate 10 forcharging the bath with 58% by weight of calcium chloride and 42% sodiumchloride comprising the charge mix 11. The temperature of the sodiumchloride and calcium chloride salt mix 11 are raised to the meltingpoint of the mixture (600° C.) by passing current through the charge mix11 between the graphite anode 12 and iron ring cathode 13 in which thesaid anode 12 and cathode 13 are separated by a circular iron screen 14which permits migration of ions but prevents direct contact of thereduced metal components of mix 11 that are gathered about cathode 13,with the chlorine gas produced at the anode. The chlorine gas isdirected upward from the molten mix 11 under hood 15 and exits from bath1 through conduit 16 to storage for recombination and future reuse.

[0024] At the elevated bath 1 temperature the calcium metal formed atthe cathode 13 is soluble with the sodium metal at said cathode 13 andthe molten sodium-calcium mixture exits bath 1 through conduit 17 andflows into heated process chamber 2 where it is admitted into pressurepump 3 through valve 18. The said pressure pump 3 forces the moltenmixture through atomizing nozzle 4 which comprises a tungsten tip forlonger wear. The molten sodium-calcium mixture is forced at highvelocity from atomizing nozzle 4 at high velocity into a atomizingchamber 6 where it passes through a blast of high pressure nitrogen gas,or other inert gases, from blast nozzle 5 and is torn apart andinstantaneously solidified as a mixture of micron size coherent mass ofsodium-calcium flocculant 8 which is directed into product bin 7. Theflocculant 8 is transferred from the said product bin 7 by screwconveyer 9 to a revolving tumbler chamber where it is thoroughly mixedwith a dehydrated talc and with trace amounts of a depolarizer agent,such as oleic acid. The finished formulation of flocculant 8, talc, anddepolarizer, hereinafter called the consumable cathode activeingredients, are then transferred by screw conveyer to a productmanufacturing bin for insertion into the said consumable electrode.

[0025] The proposed process of maintaining the calcium dissolved in themolten sodium instead of freezing it out and filtering off as the caseof the generally followed process of sodium production, and by atomizingthe molten mixture into flocculant 8 in a single heating and in asingular flowing operation at the electrolysis bath station greatlyaccelerates the production of the active ingredients and reduces thecost of the manufacture and formulation of the active ingredients of theconsumable electrode.

[0026] Turning now to FIG. 2 of the drawings. FIG. 2 shows the threemajor structural elements of the consumable electrode comprisingaluminized conductor tape 19, segmented fuel wicking element 20 andconfigured carrier insulation 21.

[0027] The said aluminized conductor tape has two longitudinal ribprotrusions 22 at each edge. The said protrusions fit within andinterlock with grooves 23 running longitudinally at each edge of thesaid carrier insulation 21. The said segmented fuel wicking elements 20fit within the compartments 24 of the said carrier insulation 21.

[0028] The segmented wicking elements 20 are comprised of the structuralelements of glass roving or fibrous paper in which the activeingredients within the sodium - calcium flocculant 8 and the dehydratedtalc and depolarizer additives have been calendered into their surfacesto the required thickness of compartments 24 of the carrier insulation21. When the conductor tape 19 and carrier insulation 21 are broughttogether enclosing the wicking elements 20 in their respectivecompartments the said conductor tape 19 and said carrier insulation 21are heat sealed cross-wise on each end of the compartments 24 at sealpoint 25 indicated by the broken line.

[0029]FIG. 3 is an assembled cross-section of the consumable electrodeelements shown in FIG. 2. In FIG. 3 the conductor tape 19 is lasersealed to carrier insulation 21 at their interface 27, or they may besealed by other means.

[0030]FIG. 4 is an assembled cross-section of the consumable electrodehaving the same elements of the cross-section of FIG. 3 and include theadditional feature of a conducting wire 28 imbeded in grove 23 ofcarrier insulation 21. The wire 28 increases the tape tensile integrityand assurance of good electrical conductivity at generator higheroperating temperatures.

What is claimed is:
 1. A method of combining in the molten state sodium(Na) hereinafter called an initiator, with calcium (Ca), hereinaftercalled a moderator, during the process of electrolysis, said moderatorbeing soluble in said initiator as a mixture at an electrolysis bathtemperature of 600° C. (1112° F.), said molten mixture of initiater andmoderator being transferred in the molten state to a process chamber andpasses through a valve at the lower end of said process chamber openinginto the inlet of a pressure pump, said pressure pump forces the saidmolten mixture of initiator and moderator into an atomizing nozzle, saidmolten mixture exits said nozzle as a high velocity stream into anatomizing chamber, where it is intercepted by an impinging blast ofinert high pressure gas and is broken up and cooled below its freezingpoint into micron size solid globules comprising a flocculant initiatorand moderator mixture, said mixture of initiator and moderatorflocculant being placed in a revolving tumbler chamber in which ameasured quantity of dehydrated talc and trace amounts of a depolarizeragent are added and thoroughly mixed to form the active ingredients of aconsumable electrode.
 2. The flocculant initiator and moderator mixtureof claim 1 being embedded into the surface of a fibrous paper bycalendering, said fibrous paper containing the embedded said initiatorand said moderator mixture being cut into wicking element segments ofregular length and width, a carrier insulation comprising regularlyspaced compartments and grooves along each edge, said wicking elementsinserted into said compartments, an aluminized conductor tape havinglongitudinal rib protrusions at each edge, said rib protrusions fittedwithin said grooves of said carrier insulation enclosing the said wickerelements within the said compartments of the said carrier insulation,said conductor tape and said carrier insulation being sealed together attheir contacting edges and sealed cross-wise between each of the saidcompartments holding the said wicking elements.
 3. The flocculantinitiator and moderator mixture and talc and depolarizer additives ofclaim 1 being embedded into the surface of a fibrous paper bycalendering, said fibrous paper containing the embedded said initiatorand said moderator mixture being cut into wicking element segments ofregular length and width, a carrier insulation comprising regularlyspaced compartments and grooves along each edge, said wicking elementsinserted into said compartments, an aluminized conductor tape havinglongitudinal rib protrusions at each edge, said rib protrusions fittedwithin said grooves of said carrier insulation enclosing the said wickerelements within the said compartments of the said carrier insulation,said conductor tape and said carrier insulation being sealed together attheir contacting edges and sealed cross-wise between each of the saidcompartments holding the said wicking elements.
 4. The flocculantinitiator and moderator mixture and talc and depolarizer additives ofclaim 1 being imbedded into the surface of a fibrous paper bycalendering, said fibrous paper containing the imbedded said initiatorand said moderator and said talc and depolarizer additives being cutinto wicking element segments of regular length and width, a carrierinsulation comprising regularly spaced compartments and grooves at eachedge, said wicking elements inserted into said compartments, wireinserted into the bottom of said grooves, an aluminized conductor tapehaving longitudinal rib protrusions along each edge, said ribprotrusions fitted within said grooves of said carrier insulationholding said wire in place in said grooves and enclosing said wickingelements within the said compartments of the said carrier insulation,said carrier insulation and said conductor tape being sealed together attheir contacting edges and sealed cross-wise between each of the saidcompartments holding the said wicking elements.
 5. The flocculantinitiator and moderator mixture and talc and depolarizer additives ofclaim 1 being embedded into the intervening space between the fibrousstrands of glass roving by calendering, said calendered strands of glassroving containing the embedded said initiator and said moderator mixturebeing cut into wicking element segments of regular length and width, acarrier insulation comprising regularly spaced compartments and groovesalong each edge, said wicking elements inserted into said compartments,an aluminized conductor tape having longitudinal rib protrusions at eachedge, said rib protrusions fitted within said grooves of said carrierinsulation enclosing the said wicker elements within the saidcompartments of said carrier insulation, said conductor tape and saidcarrier insulation being sealed together at their contacting edges andsealed cross-wise between each of the said compartments holding the saidwicking elements.
 6. The flocculant initiator and moderator mixture andtalc and depolarizer additives of claim 1 being embedded into theintervening space between the fibrous strand of glass roving bycalendering, said calendered strands of glass roving containing theembedded said initiator and said moderator mixture being cut intowicking element segments of regular length and width, a carrierinsulation comprising regularly spaced compartments and grooves alongeach edge, said wicking elements inserted into said compartments, wireinserted into the bottom of each said groove, an aluminized conductortape having longitudinal rib protrusions along each edge, said ribprotrusions fitted within said grooves of said carrier insulation on topof said wire holding said wire in place in said groove and enclosingsaid wicking elements within said compartments of said carrierinsulation, said carrier insulation and said conductor tape being sealedtogether at their contacting edges and sealed cross-wise between each ofthe said compartments holding the said wicking elements.